User Interface Resource File Optimization

ABSTRACT

Technologies described herein reduce the size of a software application. In some embodiments, the size of one or more resource files of an application are reduced. Resource files include key/value pairs that define elements of the application. In some embodiments, the application&#39;s source code is analyzed to determine if an entry in a resource file may be removed. For instance, initialization functions in the application&#39;s source code may be analyzed to determine if a value loaded from a resource file is replaced before being used. For example, a button with a color property may be defined as grey by a resource, but later set to orange in an initialization function. In this case, the resource entry defining the button as grey is superfluous and may be safely removed. This technique allows for entries to be removed from a resource file even though the source code references the entries.

RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 16/162,313, filed Oct. 16, 2018, entitled “UserInterface Resource File Optimization”, the entire disclosure of which ishereby incorporated by reference herein in its entirety.

BACKGROUND

Modern software applications can include a large number of features. Asa result, such applications can be very large in size, sometimeshundreds of megabytes or even gigabytes. As a result, softwareapplications can consume significant computing resources, such asstorage space. Significant network bandwidth can also be consumed whenlarge application programs are transmitted between computing devices,resulting in significant monetary costs. Users might also prioritizelarge software applications for deletion as compared to smallerapplications when storage is limited.

Many techniques have been utilized previously to reduce the size ofsoftware applications, including dead code stripping, file compression,and feature removal. However, these techniques are not always applicableor effective. For example, dead code stripping is applied duringcompilation, and as such does not affect code written in non-compiled(i.e. interpreted) languages. Similarly, code that is compiled “just intime”, after being downloaded to a client device, will not reduce thesize of the download. Dead code stripping is also limited by relying oncode-flow analysis, which does not consider something safe to remove ifit is later referenced by the application. File compression is limitedin effectiveness by the type of data being compressed, and has the addedexpense of requiring an expensive decompression step on the client.

However, even if these previous techniques have been applied, users andproducers may still benefit from a further reduced software applicationsize. As such, there persists a need to further reduce the size ofsoftware application size. It is with respect to these and otherconsiderations that the disclosure made herein is presented.

SUMMARY

Technologies described herein reduce the size of a software application.Generally described, the techniques disclosed herein can reduce the sizeof an application through an analysis of source code and a resource filethat enables the removal of data from the resource file that isdetermined to be duplicative or unused during runtime. Reducing filesize has many technological benefits: memory, processing, and powerefficiency are improved. Download size—the number of bytes transferredover a network to distribute the software application to a clientdevice, and install size—the number of bytes used to store theapplication on the client device, are reduced. End users experiencefaster download times, faster launch times, and increasedresponsiveness. Developers attract and retain performance sensitivecustomers while reducing distribution costs.

In some embodiments, one or more resource files, such as but not limitedto an iOS®/macOS® .nib or storyboard, or a Windows® .rc file, arereduced in size. Resource files include key/value pairs that defineelements of an application. For example, a resource file may define asize and location of a view, a color of a button, or a weight and styleof a font. Often, a resource file is generated by a visual designer,which can be an application program that enables a user interface to beconstructed using mouse and keyboard input. An application may havetens, hundreds, or more resource files, such that even small reductionsin the size of the resource files may have a large effect on the size ofan application.

In some embodiments, an application's source code is analyzed todetermine if an entry in a resource file used by the application may beremoved. An initialization function in the application's source code maybe analyzed to determine if a value loaded from a resource file isreplaced before being used. For example, a button with a color propertymay be defined as grey by a resource, but later set to orange atexecution time by an initialization function. In this case, the resourceentry defining the button as grey is superfluous and may be safelyremoved. In this embodiment, entries may be removed from a resource fileeven though the application's source code contains a reference to theentries.

By applying the techniques discussed herein, real world savings of 50 kbhave been observed for a set of already heavily optimized resource filesthat were collectively 1.5 mb in size. However, greater or lessersavings may be achieved based on the number of resource files includedin a given application, the size of those resource files, the frequencyof elements with values that were overwritten, etc. This improves onexisting techniques that analyze a resource file in isolation, or basedon tools that only remove values that are not referenced by theapplication.

It should be appreciated that the above-described subject matter can beimplemented as a computer-controlled apparatus, a computer-implementedmethod, a computing device, or as an article of manufacture such as acomputer-readable medium. These and various other features will beapparent from a reading of the following Detailed Description and areview of the associated drawings.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intendedthat this Summary be used to limit the scope of the claimed subjectmatter. Furthermore, the claimed subject matter is not limited toimplementations that solve any or all disadvantages noted in any part ofthis disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The Detailed Description is described with reference to the accompanyingfigures. In the figures, the left-most digit(s) of a reference numberidentifies the figure in which the reference number first appears. Thesame reference numbers in different figures indicate similar oridentical items.

FIG. 1 illustrates an exemplary system for reducing the size of asoftware application.

FIG. 2 illustrates an exemplary visual design tool used to generateresource files for graphical user interfaces.

FIG. 3 illustrates an exemplary resource file before optimization.

FIG. 4 illustrates an exemplary initialization function that is analyzedto determine key/value pairs that can be safely removed from theexemplary resource file.

FIG. 5 illustrates an exemplary resource file that has had superfluouskey/value pairs removed.

FIG. 6 illustrates an overview of exemplary processes for reducing thesize of a software application.

FIG. 7 illustrates an example process of reducing the size of a softwareapplication by removing values from a resource file that are overwrittenin an initialization function.

FIG. 8 illustrates an example process of reducing the size of a softwareapplication by reordering elements and properties of elements tomaximize property overlap between adjacent elements.

FIG. 9 illustrates an example process of reducing the size of a softwareapplication by removing unreferenced placeholder values from a resourcefile.

FIG. 10 shows additional details of an example computer architecture fora computer capable of executing the software components describedherein.

DETAILED DESCRIPTION

The following Detailed Description describes technologies that reducethe size of an application. Technical benefits include improving memory,processing, and power efficiency. Download size, the number of bytestransferred over a network to distribute the software application to aclient device, and install size, the number of bytes used to store theapplication on the client device, are reduced. End users experiencefaster download times, faster launch times, and increasedresponsiveness. Developers attract and retain performance sensitivecustomers while reducing distribution costs.

In common development scenarios, resource files are generated by adeveloper tool such as Apple® Xcode® or Microsoft® Visual Studio®. Forexample, Xcode allows a developer to visually define, with keyboard andmouse, the size, location, color, text, and other properties ofgraphical elements that are part of a user interface. These propertiesare stored in a resource file, such that at runtime, objectsrepresenting the elements may be recreated as they were defined inXcode. Non-visual elements may also have properties defined in aresource file.

In a resource file, resources are commonly stored as key/value pairs,grouped by element. Elements may be nested, allowing a tree of elementsto be defined. For example, a ‘UIView’ element may include key/valuepairs for ‘Bounds’ (boundaries)={0.0, 0.0, 375.0, 50.0} and‘Center’={187.5, 85.0}. In addition to defining literal values, elementsmay define ‘Sub Views’, which point to one or more child element thateach have their own list of key/value pairs. The ‘UIView’ element mayhave child labels, child buttons, or other graphical elements.

In some embodiments, at runtime, the key/value pairs associated with anelement are used to instantiate associated runtime objects. In someembodiments, the associations are defined in the resource file as a listof connections—i.e. a list that maps class member variables to elementsin the resource file. Based on this mapping, values are copied from theresource file to the corresponding object properties. For example, aresource file may include a textbox element having a text propertydefined as “the quick brown fox jumps over the lazy dog”. In this way,at runtime, the ‘Text’ property of the corresponding textbox object isset to this string. In some embodiments, this loading process occursbefore user-defined initialization functions are executed.

However, once the user defined initialization function is called, theapplication may overwrite a value that originated in a resource file.This may be done for several reasons: to localize a string, to implementa UI customization (e.g. a ‘skin’), because the value stored in theresource file is a default inserted by a developer tool that was neverintended for use, or any other reason.

The discussion above describes the context of the claimed techniques forreducing software application size discussed below. If an assignmenthappens within an initialization function, the value that was loadedfrom the resource file will be overwritten before it is used by the restof the application, and so the key/value pair can be safely removed fromthe resource file. Continuing the example, if, in an initializationfunction, the developer overwrites the ‘Text’ property of the textboxobject with the string “One fish, two fish, red fish, blue fish”, thenthe string “the quick brown fox jumps over the lazy dog” can safely beremoved from the resource file. Then, upon execution, all otherproperties of the textbox object will be loaded from the resource file,e.g. location, size, etc., but not the text itself. Thus the textboxobject will be generated as if “the quick brown fox jumps over the lazydog” was never added to the resource file in the first place.

Other information stored in a resource file may be similarly optimized.For example, data describing the state of an element, such as whether itis hidden or visible, may be encoded in a resource file. If this stateis explicitly set in the initialization function, causing the value fromthe resource file to be overwritten, then the state value in theresource file may be removed without impacting execution of theapplication. Similarly, checkbox state may have a default value set bythe resource file that is overwritten in the initialization function,allowing the resource value representing this state to be deleted fromthe resource file. Images, or file path references to images, may besimilarly pruned from a resource file if it is determined that they areoverwritten in an initialization function.

In one embodiment, when the application targets the iOS® or MacOS®platform, analysis may be performed on an initialization function suchas ‘ViewDidLoad’ or ‘AwakeFromNib’. However, any user defined functionthat executes after initialization from a resource file, but before anyother user defined code, is similarly contemplated.

As discussed above, in some embodiments, developer tools generateresource files that include values used at design time but not at runtime. These values may be defaults introduced by a design tool, or theymay be added by a developer at design time to better visualize what agraphical element will look like at run-time. To a traditional code-flowanalysis, these default values are referenced by the application (i.e.the properties populated by the default values are referenced by theapplication), and so previous techniques for identifying unused valueswould not recognize these replaced values as superfluous.

Turning now to FIG. 1, illustrated is an exemplary system 100 forreducing the size of a software application 102. As illustrated, thesystem 100 may include computing device 101 implementing resource filereducer 112. Resource file reducer 112, in some embodiments, is asoftware component that analyzes source code 114 of an application 102in order to identify ways to remove entries from storyboard 108 and/orresource files 110(a), 110(b), etc. The resulting storyboards andresource files are represented by storyboard 108′ and resource files110(a)′, 110(b)′, etc. In this way, application 102, which has alreadybeen compiled at least in part from source code 114, is reduced in size.The reduced size version of the application 102 is represented in FIG. 1by application 102′. While applying the transformation, executable code104 and images 106, among other file types included in the application,remain unchanged.

Turning now to FIG. 2, illustrated is exemplary visual design tool 200used to generate resource files that are optimized by the disclosedembodiments. Visual design tool 200 may be used by a software developerto design graphical user interfaces visually, e.g. by dragging anddropping components such as UI View 216, title label 238, center image240, description label 242, and submit button 246 onto a canvas. Adeveloper may then move, resize, delete, or otherwise edit the graphicalelements. For example, a developer may edit properties 208 of a selectedgraphical element.

As depicted, the properties of description label 242 are being edited,such as text 250, color 252, font 254, dynamic type 256, enabled state258, hidden state 260, and alignment 262. State, such as Boolean valuesenabled 258 and hidden 260, may be indicated with a check-box. For eachgraphical element, location, size, and other properties are derived fromthe position of the graphical elements within visual editor 206 andstored in a corresponding resource file 110 as key/value pairs.Similarly, properties listed in properties window 208 are stored in thecorresponding resource file 110 as key/value pairs.

In some embodiments, element tree 204 depicts a hierarchy of graphicalelements as they have been laid out by a developer. This hierarchy isreflected in the generated resource file 110. As depicted, graphicalelement UIView 216 is a parent element, representing the top-levelgraphical element depicted in visual editor 206. Child elements includeLogin Header 218, TitleLabel 238, View 222, CenterImageView 240,DescriptionLabel 242, SubmitButton 246, and BrowseEventsButton 236.CenterImageView 240 itself has child graphical elements, includingConstraint 226, which includes width 80 (pixels) 228 and height 80 230.

Turning now to FIG. 3, illustrated is an exemplary resource file 110.Resource file 110 includes a series of key/value pairs that are groupedby elements. Throughout this disclosure, the terms “properties”,“entries”, and “key/value pairs” are used interchangeably when referringto a resource file. Each element is numbered and has a name (e.g. “0:NSObject”). In the depiction illustrated in FIG. 3, the key/value pairis displayed in the form “<Key>=<Value>”, where the Key is a name andthe Value may be data or a reference to another element. However,resource files may be encoded in any number of ways, often in acompressed or encoded binary format.

Resource file 110 depicts a resource file as generated by a compiler,but before the optimizations described herein have been applied. Forexample, element 42, “UILabel”, has the key/value pair “UIBounds={0.0,0.0, 42.0, 21.0}. This property represents the boundary of the UILabelgraphical element, and is an example of a data literal stored in theresource file. At the same time, the “UIText” Key under entry 42(“UILabel”) has a Value of “@14”, where the ‘@’ sign indicates that “14”refers to element 14 of the resource file (i.e. “14 NSString”).

Turning now to FIG. 4, illustrated is an exemplary initializationfunction 402. Initialization function 402 represents user-generated code(as opposed to code generated by a tool, such as visual design tool200). In some embodiments, initialization function 402 is executed for agraphical element in response to loading values from the element'sresource file 110. By nature of being executed before any other usergenerated code, any values overwritten during initialization function402 are superfluous, and may be safely deleted from resource file 102.

For example, “self descriptionlabel.text” is a property on the“descriptionlabel” element included in the view being loaded. The valueof this property has already been set to a value retrieved from resourcefile 102, e.g. “the quick brown fox jumped over the lazy dog”. However,by determining that this property of the “descriptionlabel” element isbeing overwritten in the initialization function, resource file reducer112 may conclude that the entry containing “the quick brown fox . . . ”can be removed.

A similar analysis can be performed on other types of information storedin the resource file. For example, “selfbrowserEventsButton.hidden=NO”sets the hidden property of the browserEventsButton to no. As thisassignment is happening in code in initialization function 402, there isno use for a value stored in the resource file, whether or not the valuein the resource file is different from the value set in initializationfunction 402.

Turning now to FIG. 5, illustrated is an exemplary resource file 110that has had superfluous key/value pairs removed. Resource file 110details how a resource file may be modified by resource file reducer112. Entries that have been removed are depicted with strikethroughs forsake of clarity, but as actually implemented the entries would becompletely removed from the resource file. For example, thedescriptionLabel 242 corresponds to element 42 in the resource file,which points to the string “The quick brown fox jumped over the lazydog” via entry 14. However, based on this information, the line of code“selfdescriptionLabel.text=NSLocalizedString(g“account_has_been_verified”,nil);” depicted in FIG. 4 may be analyzed to determine that the“descipriptionLabel.text” property is overwritten. As discussed above,the purpose of overwriting the value is inconsequential.

Resource file 110 also depicts other types of key/value pairs beingdeleted. For example, entry 64 has the property “UIHidden=true”, whichwas set based on the checkbox next to the Hidden state 260 as indicatedin FIG. 2. However, the line “self.browserEventsButton.hidden=NO;” ofinitialization function 402 overwrites this value, allowing it to besafely removed from resource file 110. Similarly, the deletion of theelement 2 (NSImage) is enabled by the line “selfcenterImageView.image=[UIImage imageNamed:@“success_illustration”];”,which overwrites the value of the image in the initialization function.Resource file 110 also depicts the deletion of the placeholder“Filesowner”, as depicted by the strikethrough of element 1.

FIGS. 6-9 illustrate example processes 600, 700, 800, and 900 forreducing the size of a software application 102. The processes areillustrated as a collection of blocks in a logical flow graph, whichrepresent a sequence of operations that can be implemented in hardware,software, or a combination thereof. In the context of software, theblocks represent computer-executable instructions that, when executed byone or more processors, perform the recited operations. Generally,computer-executable instructions include routines, programs, objects,components, data structures, and the like that perform or implementparticular functions. The order in which operations are described is notintended to be construed as a limitation, and any number of thedescribed blocks can be combined in any order and/or in parallel toimplement the process. Other processes described throughout thisdisclosure shall be interpreted accordingly.

FIG. 6 illustrates an overview of exemplary processes 600 for reducingthe size of a software application 102 as described above with regard toFIGS. 1-5. In some embodiments, exemplary process 600 is implemented bycomputing device 101. While FIG. 6 describes an overview of a number oftechniques for reducing software application size, any technique, orcombination of techniques may be independently applied, and in anyorder. For example, block 601 describes a technique for removing valuesfrom a resource file that are overwritten in an initialization function.This technique may be applied alone or in combination with thetechniques described in blocks 603 and 605.

Block 601, discussed in more detail below in conjunction with FIG. 7,describes a technique for removing values from a resource file that areoverwritten in an initialization function. Block 603, discussed in moredetail below in conjunction with FIG. 8, describes reordering elementsand element properties within a resource file to increase a number ofproperties on the borders of elements that are also on the borders ofneighboring elements. Block 605, discussed in more detail below inconjunction with FIG. 9, describes removing unreferenced placeholdervalues from a resource file.

FIG. 7 illustrates an example process 700 of reducing the size of asoftware application 102 by removing values from a resource file thatare overwritten in an initialization function. At block 701, a systemmay identify, within an initialization function, a variable initializedto a value stored in a resource file. The variable may be a membervariable (i.e. field, property, etc.) of a run-time object associatedwith a graphical element. In some embodiments, the association betweenthe variable and the value stored in the resource file is based on alist of connections stored in the resource file that map graphicalelements designed by a visual designer onto runtime objects described incode.

For example, Title Label 238, a label element, may have a “Font”property that describes the font, e.g. Arial, Times New Roman, etc.,used by the label. An associated runtime object, e.g. “titleLabel”, mayhave a corresponding “.font” property. A correspondence between the“Font” property in the resource file and the “.font” property on thecorresponding runtime object may be based on a text comparison. Whensuch a correspondence exists, it is determined that the “Font” propertyof the resource file has been used to initialize the “titleLabel.font”property of the runtime object.

At block 703, the system analyzes the initialization function 402 todetermine if the variable (e.g. member variable “titleLabel.font”) isoverwritten. Assignment statements may appear in many ways, such as withan overloaded ‘=’ operator, a copy function, or the like. Assignmentstatements may be identified based on an abstract syntax tree of theinitialization function, based on a text comparison, or the like.

The source of the value assigned to the “titleLabel.font” property isimmaterial. The value overwriting the identified variable may be aconstant, loaded from a table, or generated dynamically based on othervalues in the resource file. Also, the data type of the value isimmaterial—strings, numbers, and complex data types are similarlycontemplated.

At block 705, when it is determined that the value is overwritten in theinitialization function, the value is deleted from the resource file. Inone embodiment, the value is deleted from the resource file by readingthe resource file into memory, removing key/value pairs associated withthe identified variable, and writing out a new modified copy of theresource file. However, the original resource file may also be edited inplace.

In some embodiments, the key/value pair associated with the identifiedvariable is removed. However, the resource file may be scanned to locateany references (i.e. “@xxx” values) that point to the key/value pair,and delete these as well. Then, at block 707, the application, with themodified resource file is distributed to end users for execution.

Entries may be safely removed from a resource file based on othercriteria. For example, an abstract syntax tree may be created from thesource code used to compile the application, and a code-flow analysisapplied to determine if a value loaded from a resource file is everused. This analysis may determine if the value is overwritten outside ofdesignated initialization functions, or if the value is simplyunreferenced.

In other embodiments, values associated with orphaned User Interface(UI) elements may be identified and removed. Orphaned UI elements may beintroduced accidentally, e.g. left behind after implementing “ABtesting”. AB testing inserts different versions of a user interface intoan application for evaluation by actual end users. Once, based on enduser data, a preferred user interface is identified, the remaining UIelements are intended to be removed, but may remain in the applicationunintentionally. In these cases, a code-flow analysis may determine thata particular value is never used, and so the corresponding entries maybe removed from the resource file.

FIG. 8 illustrates an example process 800 of reducing the size of asoftware application 102 by reordering elements and properties ofelements to increase a number of properties on the borders of elementsthat are in common with elements on the border of neighboring elements.At block 801, a plurality of resource groups that include one or moreresource values in a defined order are identified within a resourcefile. Resource groups may comprise elements, such as views, buttons,labels, and the like, but any collection of resource values aresimilarly contemplated. Similarly, resource values may compriseproperties, such as key/value pairs (e.g. Bounds=“{0.0, 0.0, 50.0,80.0}”, Activated=“true”, and the like), but other values are similarlycontemplated.

In some embodiments, the order of resource values (e.g. key/value pairs)in a resource collection (e.g. an element) does not impact runtimebehavior, in which case the resource values may be re-ordered before orafter the resource file has been generated. Similarly, in someembodiments, the order of resource groups in a resource file does notimpact runtime behavior, and as such may be re-ordered before or afterthe resource file has been generated.

At block 803, the plurality of resource groups are ordered so as tomaximize a number of ordered resource values that are duplicated in anadjacent resource group. This allows adjacent groups to include the sameinstance of the duplicated resource values, allowing one of the twocopies of the duplicated resource values to be deleted from the resourcefile. In some embodiments, a resource file lists resource values in asingle global list, and defines elements with a pointer to the globalresource values list and a number of (i.e. count of) resource values tobe included.

For example, if there are three elements in a resource file, the firsthaving the resource values A, B, C, and D (in that order), the secondhaving Y and Z, and the third having C, D, E, the elements may bere-ordered so that the first and third elements are adjacent. Moreover,the elements are re-ordered such that the resource values in common (Cand D) are adjacent—i.e. the final order is (first), (third), (second),not (third), (first), (second).

This optimization may be applied to any number of elements in theresource file. In some embodiments, different orderings producedifferent amounts of resource value overlap, and so some or all of thepermutations may be tried to maximize the total amount of overlap.

In some embodiments, an element may completely overlap with one or bothneighbors, such that all constituent resource values are shared with oneor both adjacent neighbors. In some embodiments, duplicate values mayspan more than a single neighbor in the same direction. For example,instead of a third element having C, D, E, if the third element hadresource value C while a fourth element had resource values D, E, then afinal arrangement of elements could be (first), (third), (fourth),(second), to allow the resource values C and D from the first element tooverlap with the C from the (third) and the D from the (fourth)elements.

In addition to re-ordering elements, resource values within elements maybe re-ordered to maximize the number of duplicate values along adjacentelements. For example, a label element may have properties such as“Bounds”={0.0, 0.0, 0.0, 0.0}, “Center”={0.0, 0.0}, “Text”=“foobar”,“Font”=“Arial”, and “TextColor”=“Red”, among others, while a buttonelement may have properties such as “Bounds”={0.0, 0.0, 50.0, 80.0},“Center”={0.0, 0.0}, “Text”=“Ok”, “Font”=“Arial”, and“TextColor”=“Blue”. In this example, two of the five properties share aname and a value, “Center” and “Font”. To facilitate overlap between thelabel and the button, and because properties may be arranged in anyorder, the label element may use the order “Bounds”, “Text”,“TextColor”, “Center”, “Font”, while the button may use the order“Font”, “Center”, “Bounds”, “Text”, “TextColor”. In this way, the“Center” and “Font” properties are on the right side of the labelelement and the left side of the adjacent button element. Note that,because order of resource values does not matter, the button may alsohave been ordered “Center”, “Font”, “Bounds”, “Text”, “TextColor” withequivalent results. In this scenario, the resource file may be editedsuch that the label element and the button element point to the same“Center” and “Font” properties.

At block 805, resource values that are duplicated in an adjacentresource group are removed. In some embodiments, the duplicated resourcevalues are removed by generating a new global list of resource valueswithout the duplicate entries.

At block 807, a resource value list based on the determined order of theplurality of resource groups is generated. In some embodiments, aresource file is generated that includes the new ordering of resourcegroups, with some or all of the resource groups defined by the newglobal list of resource values.

FIG. 9 illustrates an example process 900 of reducing the size of asoftware application 102 by removing unreferenced placeholder valuesfrom a resource file.

At block 901, a placeholder element is identified within a resourcefile. Resource files may include placeholder values that are notthemselves resources, but server as placeholders for one or moreresources. For example, file's owner and first responder placeholdersappear in all .nib files. They establish connections between a view (acanvas that contains graphical elements such as buttons, labels, etc.)and a class name referenced in source code. This is one way in which theapplication's source code can reference properties in the resource file.However, there are other ways for source code to reference a property ina resource file, such that particular placeholder elements take up spacewithout providing a useful function.

At block 903, a determination is made whether a placeholder value isbeing used. In some embodiments, a determination is made that theplaceholder value is not in use by searching a global list ofconnections included in the resource file. If any connections have theplaceholder as the source or destination of the connection, then thedata identifying the file's owner cannot be removed. Otherwise, theplaceholder may be deleted from the resource file. In some embodiments,removing placeholder entries from the resource file is performedpost-compilation, to avoid rules enforced by the compiler that requirethe placeholder values.

At block 905, when it is determined that the placeholder element is notin use, the placeholder element is removed from the resource file.

FIG. 10 shows additional details of an example computer architecture fora computer capable of providing the functionality described herein suchas, for example, that described with reference to the resource filereducing engine 112, or any program components thereof as describedherein. Thus, the computer architecture 1000 illustrated in FIG. 10illustrates an architecture for a server computer, or network of servercomputers, or any other types of computing devices suitable forimplementing the functionality described herein. The computerarchitecture 1000 may be utilized to execute any aspects of the softwarecomponents presented herein.

The computer architecture 1000 illustrated in FIG. 10 includes a centralprocessing unit 1002 (“CPU”), a system memory 1004, including arandom-access memory 1006 (“RAM”) and a read-only memory (“ROM”) 1008,and a system bus 1010 that couples the memory 1004 to the CPU 1002. Abasic input/output system containing the basic routines that help totransfer information between elements within the computer architecture1000, such as during startup, is stored in the ROM 1008. The computerarchitecture 1000 further includes a mass storage device 1012 forstoring an operating system 1014, other data, and one or moreapplication programs. The mass storage device 1012 may further includethe resource file reducing engine 112.

The mass storage device 1012 is connected to the CPU 1002 through a massstorage controller (not shown) connected to the bus 1010. The massstorage device 1012 and its associated computer-readable media providenon-volatile storage for the computer architecture 1000. Although thedescription of computer-readable media contained herein refers to a massstorage device, such as a solid-state drive, a hard disk or CD-ROMdrive, it should be appreciated by those skilled in the art thatcomputer-readable media can be any available computer storage media orcommunication media that can be accessed by the computer architecture1000.

Communication media includes computer readable instructions, datastructures, program modules, or other data in a modulated data signalsuch as a carrier wave or other transport mechanism and includes anydelivery media. The term “modulated data signal” means a signal that hasone or more of its characteristics changed or set in a manner as toencode information in the signal. By way of example, and not limitation,communication media includes wired media such as a wired network ordirect-wired connection, and wireless media such as acoustic, RF,infrared and other wireless media. Combinations of the any of the aboveshould also be included within the scope of computer-readable media.

By way of example, and not limitation, computer storage media mayinclude volatile and non-volatile, removable and non-removable mediaimplemented in any method or technology for storage of information suchas computer-readable instructions, data structures, program modules orother data. For example, computer media includes, but is not limited to,RAM, ROM, EPROM, EEPROM, flash memory or other solid state memorytechnology, CD-ROM, digital versatile disks (“DVD”), HD-DVD, BLU-RAY, orother optical storage, magnetic cassettes, magnetic tape, magnetic diskstorage or other magnetic storage devices, or any other medium which canbe used to store the desired information and which can be accessed bythe computer architecture 1000. For purposes of the claims, the phrase“computer storage medium,” “computer-readable storage medium” andvariations thereof, does not include waves, signals, and/or othertransitory and/or intangible communication media, per se.

According to various techniques, the computer architecture 1000 mayoperate in a networked environment using logical connections to remotecomputers through a network 1050 and/or another network (not shown). Thecomputer architecture 1000 may connect to the network 1050 through anetwork interface unit 1016 connected to the bus 1010. It should beappreciated that the network interface unit 1016 also may be utilized toconnect to other types of networks and remote computer systems. Thecomputer architecture 1000 also may include an input/output controller1018 for receiving and processing input from a number of other devices,including a keyboard, mouse, or electronic stylus (not shown in FIG.10). Similarly, the input/output controller 1018 may provide output to adisplay screen, a printer, or other type of output device (also notshown in FIG. 10). It should also be appreciated that via a connectionto the network 1050 through a network interface unit 1016, the computingarchitecture may enable the product of the resource file reducing engine112 to be distributed to customers.

It should be appreciated that the software components described hereinmay, when loaded into the CPU 1002 and executed, transform the CPU 1002and the overall computer architecture 1000 from a general-purposecomputing system into a special-purpose computing system customized tofacilitate the functionality presented herein. The CPU 1002 may beconstructed from any number of transistors or other discrete circuitelements, which may individually or collectively assume any number ofstates. More specifically, the CPU 1002 may operate as a finite-statemachine, in response to executable instructions contained within thesoftware modules disclosed herein. These computer-executableinstructions may transform the CPU 1002 by specifying how the CPU 1002transitions between states, thereby transforming the transistors orother discrete hardware elements constituting the CPU 1002.

Encoding the software modules presented herein also may transform thephysical structure of the computer-readable media presented herein. Thespecific transformation of physical structure may depend on variousfactors, in different implementations of this description. Examples ofsuch factors may include, but are not limited to, the technology used toimplement the computer-readable media, whether the computer-readablemedia is characterized as primary or secondary storage, and the like.For example, if the computer-readable media is implemented assemiconductor-based memory, the software disclosed herein may be encodedon the computer-readable media by transforming the physical state of thesemiconductor memory. For example, the software may transform the stateof transistors, capacitors, or other discrete circuit elementsconstituting the semiconductor memory. The software also may transformthe physical state of such components in order to store data thereupon.

As another example, the computer-readable media disclosed herein may beimplemented using magnetic or optical technology. In suchimplementations, the software presented herein may transform thephysical state of magnetic or optical media, when the software isencoded therein. These transformations may include altering the magneticcharacteristics of particular locations within given magnetic media.These transformations also may include altering the physical features orcharacteristics of particular locations within given optical media, tochange the optical characteristics of those locations. Othertransformations of physical media are possible without departing fromthe scope and spirit of the present description, with the foregoingexamples provided only to facilitate this discussion.

In light of the above, it should be appreciated that many types ofphysical transformations take place in the computer architecture 1000 inorder to store and execute the software components presented herein. Italso should be appreciated that the computer architecture 1000 mayinclude other types of computing devices, including hand-held computers,embedded computer systems, personal digital assistants, and other typesof computing devices known to those skilled in the art. It is alsocontemplated that the computer architecture 1000 may not include all ofthe components shown in FIG. 10, may include other components that arenot explicitly shown in FIG. 10, or may utilize an architecturecompletely different than that shown in FIG. 10.

In closing, although the various techniques have been described inlanguage specific to structural features and/or methodological acts, itis to be understood that the subject matter defined in the appendedrepresentations is not necessarily limited to the specific features oracts described. Rather, the specific features and acts are disclosed asexample forms of implementing the claimed subject matter.

What is claimed is:
 1. A computer-implemented method of optimizing anapplication, comprising: identifying, within a resource file, aplaceholder element; determining whether the placeholder element is inuse; and responsive to a determination that the placeholder element isnot in use, removing the placeholder element from the resource file. 2.The computer-implemented method of claim 1, wherein the placeholderelement is a placeholder for one or more resources.
 3. Thecomputer-implemented method of claim 1, wherein the determination ofwhether the placeholder element is in use is based on a global list ofconnections between elements and classes defined in a source code file.4. The computer-implemented method of claim 1, wherein the removal ofthe placeholder element is performed post-compilation.
 5. Thecomputer-implemented method of claim 1, wherein the placeholder elementcomprises a FilesOwner or a FirstResponder entry.
 6. Thecomputer-implemented method of claim 1, wherein the determination thatthe placeholder element is not in use is made based on the placeholderelement being an unreferenced placeholder element.
 7. A systemcomprising: one or more processing units; and a computer-readable mediumhaving encoded thereon computer-executable instructions to cause the oneor more processing units to: identify, within a resource file, aplaceholder element; determine, based on a global list of connectionsbetween elements and classes defined in a source code file, whether theplaceholder element is in use; and remove, responsive to a determinationthat the placeholder element is not in use, the placeholder element fromthe resource file.
 8. The system of claim 7, wherein the placeholderelement is a placeholder for one or more resources.
 9. The system ofclaim 7, wherein the determination of whether the placeholder element isin use is based on a global list of connections between elements andclasses defined in a source code file.
 10. The system of claim 7,wherein the removal of the placeholder element is performedpost-compilation.
 11. The system of claim 7, wherein the placeholderelement comprises a FilesOwner or a FirstResponder entry.
 12. The systemof claim 7, wherein the determination that the placeholder element isnot in use is made based on the placeholder element being anunreferenced placeholder element.
 13. The system of claim 7, wherein thedetermination that the placeholder element is not in use is made basedon determining that the resource file does not include connectionsbetween a user-supplied programming object and graphical elementsdefined in the resource file.
 14. A non-transitory computer-readablemedium comprising a set of instructions that, when executed by at leastone processor of a computer system, cause the computer system to performoperations, the operations comprising: identifying, within a resourcefile, a placeholder element; determining whether the placeholder elementis in use; and responsive to a determination that the placeholderelement is not in use, removing the placeholder element from theresource file.
 15. The non-transitory computer-readable medium of claim14, wherein the placeholder element is a placeholder for one or moreresources.
 16. The non-transitory computer-readable medium of claim 14,wherein the determination of whether the placeholder element is in useis based on a global list of connections between elements and classesdefined in a source code file.
 17. The non-transitory computer-readablemedium of claim 14, wherein the removal of the placeholder element isperformed post-compilation.
 18. The non-transitory computer-readablemedium of claim 14, wherein the placeholder element comprises aFilesOwner or a FirstResponder entry.
 19. The non-transitorycomputer-readable medium of claim 14, wherein the determination that theplaceholder element is not in use is made based on the placeholderelement being an unreferenced placeholder element.
 20. Thenon-transitory computer-readable medium of claim 14, wherein thedetermination that the placeholder element is not in use is made basedon determining that the resource file does not include connectionsbetween a user-supplied programming object and graphical elementsdefined in the resource file.